THE DISTRIBUTION AND EFFECTS OF INHALED PU-239(NO3)(4) DEPOSITED IN THE LIVER OF DOGS

The distribution and effects of inhaled Pu-239(NO3)(4) deposited in th e liver of dogs were studied in five groups of 20 beagles exposed to i nitial lung depositions ranging from 1.0 to 520 Bq g(-1) lung. Followi ng life-span observations, the liver contained 40 +/- 1% of the final body deposition of plutonium, second only to the skeleton. The liver-t o-skeleton ratio of deposited plutonium for total organ was 0.8, or 3. 5 when expressed on a per-gram basis, There was no effect of exposure level on liver-to-skeleton ratios, Autoradiographs showed that the dos e rate delivered to parenchymal cells was higher than evident from rad iochemical analysis of the whole organ, Elevated levels of serum liver enzymes were observed in groups with mean liver concentrations of 1.3 Bq g(-1) and liver doses of 3 Gy or higher, Nodular hyperplasia of li ver and bile-duct hyperplasia were observed, Liver tumors, principally of bile-duct epithelium, were late-occurring and mere observed at low er exposure levels at which life span was not shortened by lung or bon e tumors.